Whatever the number it is, bear it in mind as we show you what we found today at a middle school outside of chicago. The beckers, thomass, the pickets, ramsees, the murks. In total, 24 sets of twins all in the fifth grade in wil met, illinois. Hello, world news! Reporter: As you may have noticed, most are fratternal. There are two sets of identical twins, though. But these stories starts with these twins, ryan and luke, who were thumbing through the guinness book of world records a few months ago and saw that the current record for most twins in a single class is held by a houl in iowa. 16. Wow, I think we might have a world record. Reporter: They called the people at guinness who have asked for official documentation, including birth certificates and a group picture. It was pure excitement. Twins have long been the source of fascination, the subject of viral videos, like these two boys debating nuclear thermal dynamics in their own secret language. Reporter: There is no science to suggest twins have esp or anything like that, but they do have powerful bonds. Are you both here? Reporter: There is no science to suggest twins have esp or anything like that, but research does confirm they have powerful bonds. It's nice to know there's someone out there who is exactly like you. In the past 30 years, there's been a 75% increase in twins driven by fertility treatments which increase the odds of multiple births. I think it's really cool that there's so many twins. Reporter: Doctors are now getting better at ensuring single pregnancies, so the twin rate is likely to drop, which means the kids here could hold the world record for a long time.

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